First, referring to FIGS. 10 to 13, the constitutions and structures of a semiconductor device and a semiconductor module according to the related art will be described.
FIG. 10 is a sectional view of a semiconductor device according to one embodiment of the related art, FIG. 11 is a sectional view of the structure in which the semiconductor device shown in FIG. 10 is mounted on a mother board, FIG. 12 is a sectional view of a semiconductor module in which a plurality of semiconductor devices shown in FIG. 10 are mounted on a mother board, and FIG. 13 is a sectional view of a semiconductor module according to another embodiment in which a plurality of semiconductor devices shown in FIG. 10 are mounted on a mother board.
First, the constitution and structure of a semiconductor device according to one embodiment of the related art will be described by use of FIG. 10.
The semiconductor device C is comprised of a semiconductor integrated circuit chip (hereinafter referred to simply as “IC chip”) 1 and a printed wiring board 110. On the surface of the IC chip 1, a plurality of bump 2 of gold, solder or the like are provided on the surfaces of electrodes formed in a predetermined arrangement. On the surfaces of an electrically insulating substrate 111 of the printed wiring board 110, a plurality of lands 113 corresponding to the bumps 2 are provided at peripheral portions of a mount portion 112 on the face side for mounting the IC chip 1, while a plurality of external connection electrodes 114 are provided in a peripheral arrangement or a lattice arrangement on the back side, and a plurality of via holes 117 for electrical connection between the lands 113 on the face side and the external connection electrodes 114 on the back side are provided.
The IC chip 1 is mounted on a central portion of the printed wiring board 110 by use of an adhesive Sa or the like, and the individual bumps 2 are electrically connected to the corresponding lands 113 by use of metallic thin wires W of gold or the like. The semiconductor device C has a constitution in which the whole part of the IC chip 1 inclusive of the connection portions between the metallic thin wires W and the lands 113 is sealed with an insulating sealing material P such as an epoxy resin.
Semiconductor modules D, D1 and D2 shown in FIGS. 11 to 13 each have a structure in which a plurality of semiconductor devices C having the above-mentioned structure are mounted on a mother board 20. On the face side of the mother board 20, a plurality of lands 214 are provided at positions corresponding to the external connection electrodes 114, lands 224 (FIG. 12) are provided on the back side, and, if required, via holes 217 communicating to the back side or the like are provided. FIG. 11 shows enlarged the condition where a single IC chip 1 is electrically connected to the lands 214 on the face side of the mother board 20 having the above structure by use of, for example, soldering or other similar method. Symbol Sb denotes solder.
The semiconductor modules D1 and D2 shown in FIGS. 12 and 13 each have a constitution in which two IC chips 1 shown in FIG. 10 are mounted on the lands 214 on the face side of the mother board 20 by a soldering method, while a single IC chip 1 is mounted on the land 224 on the back side of the mother board 20 by a soldering method, and, in addition, a plurality of chip parts 30 such as resistor and capacitor are mounted. The semiconductor module D1 shown in FIG. 12 has a structure in which external connection terminals 24 connected to the lands 214 and 224 and functioning for insertion into and connection with a socket (not shown) of other electric circuit board are provided at one end of the mother board 20. The semiconductor module D2 shown in FIG. 13 has a structure in which a connector 26 or the like connected to the land 224 and functioning for connection to other electric circuit board through a flexible cable wiring board 25 is provided at one end of the mother board 20.
The semiconductor device C and the semiconductor modules D, D1 and D2 having the above-mentioned structures and constitutions are disclosed in U.S. Pat. No. 5,216,278 and ASIC & EDA, March, 1993, pp. 9–15, and are each a known one sealed in the form of “OMPAC” by Motorola, or the like.
However, such structures of the semiconductor device C and the semiconductor modules D, D1 and D2 have the problems that large numbers of printed wiring boards 110 and mother boards 20 must be used, cost is high, and a compact constitution cannot be achieved.
The present invention aims at solving the above-mentioned problems. Accordingly, it is an object of the present invention to provide a semiconductor device and a semiconductor module which can be inexpensively constituted with a compact structure.